Some recent threads got me thinking a little bit about the L88 engine, and even seeing a few in operation I am more than a little intrigued. I would like to know a lot more about the L88, and what makes it unique.

Does anyone have a lot or a source for all the specs and all the parts and measurements and everything all the way down to the cam specs?

I would be interesting to plan a modern budget version using an after market block or a modern factory roller block.

 

DB, IMHO the L-88 wasn't that unique from an engine perspective - just a high-compression engine with a big cam. I've got all the specs and a DD Advanced model if you want 'em. For the price, there are to many other good options unless you really want one "the way it was". I understand that - I had planned to build a 1970 LT-1 for the same reason

My personal all-time dream engine was the aluminum version...and I actually bought a ZL-1 block when they were re-introduced by GM. But I sold it after it sat for a number of years...and now my dream engine is just a 427 CID LS

 

Yeah I would love that information, if nothing else just to learn more about the L88. It's a big part of Corvette history and I am interested in knowing more about it and it's parts.

 

Matt,
I was an apprentice mechanic in a Chevy dealer back in 68 working in the Corvette shop. We had a customer that bought an L-88 thinking it would be more economical than a 435 because it only had a 4V carb on it! I got to do the pre delivery inspection on it which includes a thorough road test. My impresion was "wow this is unbelievable"! Having road tested a few 435's I was wondering how this thing was only rated at 430 hp and pulled like it did. Years later I learned why Chevy discouraged dealers from selling them. I wondered why at the time anyone would buy a car with no creature comforts at all.

To make a long story short he traded it in a few weeks later as it was not a streetable car at all. He ended up with a 400 horse version and was a much happier owner. The L-88 ended up on the dealers used car lot and was never seen again. I wish I knew then what I know now as it would have been in my garage. We could purchase used cars for 100.00 over what they had them actual cash valued at.

 

A 5140 427 crankshaft is pretty affordable, and some dart pro 1 heads a weiand team g for a dominator carb and call cammotion and tell them what you want and what your trying to do.

Goto town.

 

Amazing story. I have always been fascinated with the mythical L88 and dream of the posibility of owning one someday . Imagine all that power put to the street on bias ply tires. Then factor in bad weather. It's no wonder the car wasn't streetable.

 

I think OD transmissions just came too late. I believe that an L88 in front of a well built over drive transmission would do very well for streetability.

 

 

.I`ll try to remember the major differences that made it unique as opposed to a L72 just for comparison as they both started with the same block in 1966.

the major differences, codes first

TO---IP, L72,
TO---IT, L88

12.5-1 pistons with full floating pins as opposed to 11-1 press fit pins
Basically the same heads except aluminum with copper head gaskets
560/580 Camshaft as to 519/519
Flash chromed 'Pink' rods on the small end with 3/8 bolts.
Dual plane intake with open plenum
TI electronic distributor plugged vacuum, centrifugal only,
There were running small changes on both engines of really insignificant value, push rods, cam. and rod bolts for a few L88 changes

I have never seen a L88 with open chamber heads contra to some opinions here. I also didn`t buy a 69 engine to compare. But the open chamber heads came for the 1970 model run 454 smog engines with different piston domes. If there was a open chamber 427, the pistons would no longer be the same. It would have required a bigger dome and I do not know of two different L88 piston numbers, and that would have been required. I did purchase at least 10 complete crate L88`s for approximately 1200.00 each through 1967 and 68 and put them in everything where a 396 was {My 68 El Camino} or in drag boats. In conclusion the L88 has a "IT" suffix and is merely a hopped up 1966 L72 with the "IP" suffix.

The L71 and L89 are the tri power engines with the L89 getting aluminum heads. Otherwise they are almost the same as the 1966 L72`s. And then we have the LS7, another animal just bigger.

Well thats most of the differences except the Horsepower, 425/L72 to 430/L88 and we all know thats a joke for both of them... .Amazing engines and with only one 4 bore. My 1965 A990 Race Hemi needed a crossram with two and Ford dedicated to be last even with two 4 bores. No wonder the Detroit Lions are lousy, A Ford owns them...
.

 

Most beleive that the Open Chamber Head L-88 came after the Factory came back from the Strike in 69. Nobody really knows for sure when the 074 Head was put on the production Cars. I don't think there was a Piston Change. The Open Chambers claim to fame was that it made more power with less Compression. On e-bay I have seen 074 Heads with Casting Dates in 68. Most all L-88 Parts sold were across the Parts Counter rather than the Showroom Floor. Therefore they are all readily avalable. I have a 69 Custom Car that shows some sign of being an original car.

 

I own a date coded 1967 L88 full engine. 7115 tufftrided cross drilled
crank, dimple rods with 7/16 boron rod bolts, 12.5 pistons, mechanical
cam, 7/16 pushrods. I am putting it in my 67 roadster with all parts
to clone under hood. Its a violent motor and sounds like no other.
Mine has the open chamber 074 heads and open chamber pistons to match. Not a street motor because of the compression but I have
plenty of av gas which is perfect for this engine.

 

If you had an OD transmission would you still need av gas????

 

Ill let you figure that one out

 

This book may help. I haven't received mine yet, so I can't tell you what is in it.

www.thel88corvette.com

 

There is a very nice 69 monaco orange L71 car with a L88 similar to what Matt is suggesting on ebay. Overdrive car but he dropped the comp ratio to 10.5. The engine needs the 12.5 with the other components to be the beast it was intended to be.

 

I ordered one as well and was at the bloomington show this year to see the awesome event of the L88 cars under one roof.

 

Probably, since you could order your original L-88 with a beefed up TH400.

 

A guy came to my house to buy some parts, in a big Chevy dually truck with a 454. Sounded like a top fuel car, and he said he had close to 15.0:1 compression and ran on E85. Think that's true or was he talking out of his butt? Sure smelled like E85 from the exhaust and it didn't sound normal.

 

I would like to see someone build an clone L88 to exact factory specs and put it on an engine dyno and see what HP it actually made, someone has probably done it but I have never seen the numbers, the myth goes on.

Other than that why bother, not pump gas friendly compression ration and you can make a ton more HP these days with modern parts.

 

-solid lifter, .540/.560 lifts, 264/269 duration, 112 lobe centerline (1967 thru mid-1969, closed chamber heads)

-solid lifter, .560/.600 lifts, 262/273 duration, 110 lobe centerline (mid to late 1969, open chamber heads, also used ZL1, LS7)